Enabling EIGRP for IPv6 (EIGRPv6) on Cisco IOS — required configuration elements Which of the following configuration lines are used together to enable EIGRP for IPv6 on a Cisco router (assume autonomous system 10)? Select the correct combination that completes a working setup.

Introduction / Context:
Enhanced Interior Gateway Routing Protocol for IPv6 (EIGRPv6) uses a process-based configuration model. Unlike classic EIGRP for IPv4, EIGRPv6 requires you to create and start an IPv6 EIGRP process and then enable that process on participating interfaces. Understanding the exact sequence and context of commands is essential to bring adjacencies up and advertise prefixes correctly.

Given Data / Assumptions:

• The autonomous system number is 10.
• We are using standard Cisco IOS style configuration.
• At least one interface has IPv6 enabled and is up/up.

Concept / Approach:
EIGRPv6 requires three parts: (1) create the EIGRP for IPv6 process under global configuration, (2) ensure the EIGRPv6 process is administratively enabled with no shutdown (this is mandatory for EIGRPv6), and (3) activate EIGRPv6 on desired interfaces using ipv6 eigrp . There is no network statement model as with IPv4. Interface-level enablement controls which links participate in the protocol.

Step-by-Step Solution:
Enter global config and create the process: ipv6 router eigrp 10.Inside the EIGRPv6 process context, issue: no shutdown.On each participating interface, enable the process: ipv6 eigrp 10.Verify neighbors with show ipv6 eigrp neighbors and routes with show ipv6 route eigrp.

Verification / Alternative check:
Use show running-config to confirm the router configuration blocks. The presence of the process with no shutdown and interface-level activation indicates a correct setup.

Why Other Options Are Wrong:

• A: Mixes OSPFv3 with EIGRP; protocols and contexts do not match.
• C: Uses RIPng context and an EIGRP interface command together, which is invalid.
• D: The process must be enabled and attached to interfaces; no shutdown alone is insufficient.
• E: Interface-only configuration fails because the router process must exist and be active.

Common Pitfalls:
Forgetting the no shutdown inside the EIGRPv6 process or assuming IPv4-style network statements apply to IPv6. Both will prevent adjacency formation.

Final Answer:
Router1(config)# ipv6 router eigrp 10; Router1(config-rtr)# no shutdown; Router1(config-if)# ipv6 eigrp 10